Add new test of large 2D grids for CAM3 and RRTMG.
Add new test of large 2D grids for CAM3 and RRTMG.

This is expected to fail due to https://github.com/brian-rose/climlab/issues/95

cjcardinale/climlab,cjcardinale/climlab,cjcardinale/climlab,brian-rose/climlab,brian-rose/climlab